Java calculate number of weeks between two dates

/**
 * @author lautturi.com
 * Java example: calculate number of weeks between two dates in java
 */

import java.util.*;
import java.util.concurrent.TimeUnit;
import java.time.*;
import java.text.ParseException;
import java.text.SimpleDateFormat;

public class Lautturi {

	public static void main(String[] args) throws ParseException {
		SimpleDateFormat myFormat = new SimpleDateFormat("yyyy-MM-dd");
		String classStartData = "2019-10-13";
		String classEndData = "2020-01-01";

		Date dateClassStart = myFormat.parse(classStartData);
		Date dateClassEnd = myFormat.parse(classEndData);

		long differenceWeek = dateClassEnd.getTime() - dateClassStart.getTime();
		int weeks = (int)(TimeUnit.DAYS.convert(differenceWeek, TimeUnit.MILLISECONDS)/7);
		System.out.println("weeks between two dates: " +weeks);
	}

}

output:

weeks between two dates: 11